Siimes A S, Välimäki I A, Antila K J, Julkunen M K, Metsala T H, Halkola L T, Sarajas H S
Cardiorespiratory Research Unit, University of Turku, Finland.
Pediatr Res. 1990 Apr;27(4 Pt 1):383-91. doi: 10.1203/00006450-199004000-00012.
We studied the role of the autonomic nervous system in the regulation of heart rate variation (HRV) in 12 chronically instrumented neonatal lambs. HRV was quantified from ECG tracings by computing periodic HRV distributions at frequencies of 0.02-1.00 Hz, using power spectral analysis of heart rate, and also by HRV indices. Heart rate declined more during the 1st than the 2nd mo after birth. Multiple regression analysis showed that the heart rate responses to vagal and to beta-adrenergic blockade had an independent negative association both with age and with the initial mean heart rate, whereas the overall HRV response had a positive association with age. Vagal blockade led to a 70-80% decrease in the beat-to-beat HRV in all lambs (p less than 0.001). The overall HRV indices decreased by 40-65% in lambs (less than 30 d old (p less than 0.001) and about 30% in those greater than 30 d old (p less than 0.05). In the power spectrum the greatest decrease was seen in the high-frequency components of HRV. beta-Blockade led to a decrease of about 50% in all HRV (p less than 0.001) in the younger lambs, without frequency selection. In the older lambs, it had no effect on the beat-to-beat HRV, but the overall HRV (coefficient of variance) decreased maximally by 40% (p less than 0.01), with a significant reduction in the low-frequency components of HRV. These results suggest that in the regulation of HRV after birth dual control via the autonomic nervous system is most important. In the older lambs, developmental changes result in precise regulation of the fast heart rate fluctuations mainly by the vagal division, whereas the slow fluctuations are partially regulated by the vagal and beta-adrenergic divisions.
我们在12只长期植入仪器的新生羔羊中研究了自主神经系统在心率变异性（HRV）调节中的作用。通过使用心率功率谱分析计算0.02 - 1.00Hz频率下的周期性HRV分布以及HRV指数，从心电图描记中对HRV进行量化。出生后第1个月内心率下降幅度大于第2个月。多元回归分析表明，心率对迷走神经和β - 肾上腺素能阻滞剂的反应与年龄和初始平均心率均呈独立的负相关，而总体HRV反应与年龄呈正相关。迷走神经阻滞导致所有羔羊逐搏HRV降低70 - 80%（p < 0.001）。小于30日龄的羔羊总体HRV指数降低40 - 65%（p < 0.001），大于30日龄的羔羊降低约30%（p < 0.05）。在功率谱中，HRV的高频成分下降最为明显。β - 阻滞剂使较年轻羔羊的所有HRV降低约50%（p < 0.001），无频率选择性。在较年长的羔羊中，它对逐搏HRV无影响，但总体HRV（变异系数）最大降低40%（p < 0.01），HRV的低频成分显著减少。这些结果表明，出生后在HRV调节中，通过自主神经系统的双重控制最为重要。在较年长的羔羊中，发育变化导致主要由迷走神经分支精确调节快速心率波动，而缓慢波动部分由迷走神经和β - 肾上腺素能分支调节。
